1. Field of the Disclosure
The invention relates to a changer for optical elements and to an optical device, in particular a surgical microscope, a stereo microscope, a microscope, an endoscope or a stereo endoscope, containing such a changer.
2. Description of the Related Art
Changers for optical elements have already been well known. For example, DE 78 21 689 U1, DE 22 54 718 and DE 103 12 644 know a filter wheel as a rotatable, circular changer for an optical path. DE 103 12 644 thus introduces a possibility for equipping the filter wheel laterally in a simple manner.
It is already known from EP 0248 974, DE 198 35 070 and DE 103 36 890 to displace by rotation relative to one another in a single optical path two consecutively arranged changers, each changer comprising a set of filters, so as to attain a large number of different combinations.
The attempt of lightweight construction by means of recesses in the support of the optical elements is also known from EP 0248 974.
The giant disadvantage of all of these solutions is the large lateral space requirement, which can even be more than one order of magnitude above the dimensions of the cross section of the optical path, which is to be influenced.
The mere approach of the multi-changer from U.S. Pat. No. 4,600,976 with a slightly smaller, but still considerable space requirement on the side, thus perpendicular to the optical path, than in the above-mentioned documents, is interesting. However, this multi-changer is still quite large and is substantially expanded along the optical path, thus parallel to it. The elements can be pivoted in easily, but they must be mechanically controlled individually, which is already complicated. The introduction of the optical elements into the optical path takes place by means of a rotary motion.
The mere approach of DE 198 32 973 comprising a similar filter magazine as in U.S. Pat. No. 4,600,976 is also interesting because of the large possible number of optical elements, which can be introduced. However, the insertion and removal of the optical elements takes place by means of a linear motion with the help of an electromagnet. The arrangement cannot be controlled easily, it is still large and slow, energy-consuming and developmentally extensive.
U.S. Pat. No. 3,255,666 comes close to DE 198 32 973, but with manual filter insertion instead of by means of an electromagnet. DE 197 02 967, which describes a fully-automatic filter exchange, also comes close, with the filters being particle filters.
DE 197 02 754 furthermore describes a possibility for changing filters, without removing the filter wheel from the device.
Stereo optical paths or two or more spatially connected optical paths, respectively, each having a filter wheel in each case for a single optical path, can be found in DE 10 2006 006 014, DE 10 2006 004 232 and DE 103 36 890.
The disclosure of the documents cited in this application is fully adopted herewith by reference.
The disadvantage of the changers, which are offered by the state of the art, is that the optical elements, which are to be pivoted in, are arranged perpendicular to the optical path and outside of the already available space, not only in the active position, thus pivoted into the optical path, but also in the non-active position, outside of the optical path. However, due to the fact that the shape of the optical devices follows the optical path in most cases, the non-active optical elements project from the original arrangement, take up a lot of space, interfere with the orientating view past the device to the object space/operating space and the access to the object space/operating space and cause an additional housing volume and surface and thus also an additional weight, which cannot not be neglected. In addition to the direct component, this additional weight also has an indirect component due to the additional effort in response to actuation and counterweight in the case of movable optical devices, such as surgical microscopes. In general, the additional weight and volume is highly disadvantageous in the case of all optical devices, in particular from the consumer sector, such as cameras or webcams, e.g.
Additional space must be reserved for the changers according to the state of the art, because typically, there is no excess space, which could be used for optical elements in a non-active position, in the case of optical paths, which are operated individually by means of the changers.
Such solutions are particularly troublesome or cannot be accepted at all, respectively, in the endoscopes or surgical microscopes. An endoscope would have to multiply its cross section or would lose a considerable amount of resolution by means of the constriction of the optical path. In the case of a surgical microscope, a filter wheel blocks the orientating view past the microscope (see, e.g. DE 103 36 890, paragraph [0012]) and prevents a simple original positioning of the surgical microscope and of the surgeon's hands as well as a rough orientation during the operation. Due to the fact that the original positioning as well as the orientation must oftentimes be established several times during an operation, a surgical microscope comprising changers according to the state of the art is not very ergonomic. The solution proposed in DE 103 36 890 of arranging the changer closer to the top in the optical path does not keep the physician from straining his neck any less or to maintain the optical ergonomic operating position. This proposal is not a sustainable solution for the problem.
Large changer wheels are slow, require large torques and some expenditure of energy, so as to be moved and positioned. The linear (filter) inserting devices are also long, slow and cannot be moved in a low-energy manner.
The automatic filter magazines known from DE 198 32 973 and DE 197 02 967 offer an advantage in response to the use of many filters. In the case of two to six filters, as required in the case of the surgical microscopes, however, they represent a technical overkill, while still requiring too much space.